, 
1883. | Botany. 783 
are safe in saying that the study of these minute organisms, pre- 
senting as they do such a vast variety of curious and beautiful 
forms, cannot fail to be of the deepest interest to the student of 
nature, and may yet lead to good results. To contribute then to 
this end and enlist perhaps new workers in the mycological field, 
it is proposed in some succeeding apers to notice briefly some of 
the microscopic Fungi, their habits and places of growth, and the 
way to find them out. 
cavity of the aforesaid pustules, which are technically called 
Spermogonia from two Greek words signifying spore generators. 
Just what part these spermogonia play in the growth cycle of the 
fungus to which they belong is not yet certainly known. They 
are, however, intimately connected with the Aecidium, which 
again is now considered as only the first of three stages of 
growth of a polymorphic, or rather trimorphic fungus, of which 
the last and highest stage (teleutospores) is a Puccinia or Uro- 
myces. In many species there comes in between these two another 
form called Uredo, of which the spores, very similar to those of 
the Aecidiums, are produced in subcuticular clusters not con- 
tained in cups as in Aecidium, but which, when the cuticle which 
at first covers them soon breaks away, are exposed on the surface 
of the leaf, which, from this cause, appears as if covered with 
little. heaps of yellow, or reddish-yellow dust. The Aecidium 
and Uredo are oftener on the under surface of the leaf, but some- 
times on both sides. Í 
now one wishes to see some of these curious productions of 
which so much has been written within the past few years, it is 
only necessary to provide an ordinary pocket lens, such as may 
be had at the opticians for twenty-five or fifty cents, and a tin box 
Or pail with a tight-fitting cover, in which fresh leaves or flowers 
may be kept without wilting and brought home for further ex- 
amination, and go out into the nearest field to see what can | 
und. At this date (May 21st) the leaves of the various species 
Ranunculus may be examined for Aecidium ranunculacearum, 
Which is now beginning to appear. The same species is also to 
